This invention relates to an intravenous catheter assembly, and more particularly concerns an intravenous catheter assembly which has the capability for the user to manipulate the same to restrict fluid from passing therethrough.
Many intravenous catheters which are employed to deliver intravenous solution to a patient are initially inserted into that patient's vein in combination with an introducer needle. Generally, the needle is a sharp-pointed cannula which fits inside the catheter. Both are inserted into the patient's vein, the sharp point of the needle leading the way. After the combined catheter and needle are in position, the needle is withdrawn and the intravenous infusion set or other appropriate device is connected to the hub end of the catheter for delivering fluid to the patient. Before the infusion set hook-up is connected, however, there may be a problem of blood flowing out of the intravenous tubing after the needle has been removed, inasmuch as one end of the catheter remains inserted in the patient's vein. Most of the prior efforts to prevent outflow of blood from the intravenous catheter have been made by sealing its back end with an elastomeric seal of some type, and then inserting the cannula of the needle through the seal and into its position into the catheter. These devices have been prone to failure because of the tendency for the elastomeric seal to take a set during storage. The alternative of inserting the introducer cannula through the elastomeric seal immediately before the device is to be used is extremely inconvenient.
Various wing-type cannula devices have been proposed which provide a fluid-tight fit of a catheter tubing which has been inserted therein. For instance, in U.S. Pat. No. 4,006,744 a cannula mount is provided with an intermediate length of flexible tubing which is compressed around the catheter tubing after being inserted therein in order to provide a fluid-type fit. To produce this fit, a hinged jaw is closed onto another jaw to clamp the cannula portion inside the flexible tubing. Other holders for tubular items such as injection cannulae are disclosed in U.S. Pat. Nos. 3,834,380; 3,589,361; and 3,472,232. In these references, wing portions of the particular devices are employed to clamp or hold the tubular item in place, e.g., after venipuncture has occurred. While the inventions disclosed in these references provide a fluid tight seal between a catheter and a flexible holder, they are silent as to the prevention of fluid from flowing through the clamped catheter or tube. In other words, even by employing the devices disclosed by these references and other devices known in the art, the problem of blood flowing out from the catheter, especially immediately after the needle has been removed, has remained unsolved.